231555840 has 144 divisors (see below), whose sum is σ = 755854848. Its totient is φ = 60387328.

The previous prime is 231555809. The next prime is 231555847. The reversal of 231555840 is 48555132.

It is not an unprimeable number, because it can be changed into a prime (231555847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 179839 + ... + 181121.

It is an arithmetic number, because the mean of its divisors is an integer number (5248992).

Almost surely, 2^231555840 is an apocalyptic number.

231555840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 231555840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (377927424).

231555840 is an abundant number, since it is smaller than the sum of its proper divisors (524299008).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

231555840 is a wasteful number, since it uses less digits than its factorization.

231555840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1354 (or 1340 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 33.

The square root of 231555840 is about 15216.9589603179. The cubic root of 231555840 is about 614.0709881247.

The spelling of 231555840 in words is "two hundred thirty-one million, five hundred fifty-five thousand, eight hundred forty".